“Liquid Biopsy” for Lung Cancer

The majority of lung cancers are non-small cell carcinomas and about 1 in 5 of those have actionable EGFR mutations that can be treated with tyrosine kinase inhibitors (TKIs), such as erlotinib or gefitinib. Detection of these genetic markers usually involves genotyping of tissue biopsy material. A new “liquid biopsy” may soon change all that. New testing reported recently, using saliva, was able to detect these actionable EGFR mutations with 100% concordance with biopsy-based genotyping. Similarly, plasma genotyping (from blood sampling) for EGFR and KRAS mutations were rapid and accurate. Not only is this testing more rapid (minutes to days versus days to weeks) but it is less significantly expensive, especially if surgical procedures can be avoided. This technology may some day eliminate the need for surgical biopsy. Research and clinical trials are ongoing.